Quick pull valve and seat assembly

ABSTRACT

A valve seat assembly comprises a valve. The assembly further comprises a removable upper seat associated with the valve. The assembly further comprises a lower seat configured to be inserted into a fluid end of a pump and releasably couplable to the upper seat. The upper seat is decouplable from the lower seat while the lower seat remains inserted in the fluid end of the pump. The valve is configured to contact the upper seat to prevent a flow of fluid through the fluid end of the pump.

PRIORITY

This application is a continuation of U.S. application Ser. No.16/748,458, filed Jan. 21, 2020, now U.S. Pat. No. 10,815,989; whichclaims the benefit of U.S. Provisional Application 62/798,767, filedJan. 30, 2019 and U.S. Provisional Application 62/870,307, filed Jul. 3,2019, all of which are incorporated in their entirety herein byreference.

BACKGROUND

Well service positive displacement pumps face a challenge not typicallyseen. The fluid carries proppant, a very hard and abrasive particulateincluding sand. This is especially wearing on components within thepump's fluid end, and the fluid end itself. Both suction valves anddischarge valves within the pump must close upon proppant laden mediawith every stroke of the plunger. Proppant is pulverized while it grindsbetween the strike face of the valves and their seats. Despite employingvery hard materials, the valves and seats have to be replaced relativelyoften. Small leaks between the valve and seat quickly result in washedout metal, since the high pressure abrasive fluid cuts through metal.

The valve seat in a conventional well service pump has a taperedinterference press fit with the pump's fluid end. The pump's fluid endweighs thousands of pounds and is very expensive relative to theinternal components such as the valve seats. The great expense of thefluid end is one reason traditional seats are pressed in with suchinterference that it can require a hydraulic jack delivering tons offorce to pull a worn seat. A leak past the seat and fluid end usuallyresults in fluid abrasion into the fluid end rendering the fluid endscrapped. Each time a tapered seat is pulled from a fluid end, there isa risk of contaminants such as sand not being properly removed andpotentially providing a leak path between the tapered seat and the fluidend. Therefore, a need exists for a valve and seat assembly thatprevents leak paths between the seat and the fluid end of the pump,where the seat is easily replaceable.

Accordingly, there is a need for additional well service valve and seatassemblies that may address at least one of the deficiencies in thestate of the art, whether stated above or unstated.

BRIEF SUMMARY OF THE INVENTION

In the systems and devices of the present disclosure, the fluid end istapered to receive a press fitted seat. A lower seat section presses atapered fit into the fluid end. An upper seat fits within the lower seatand relies on a seal to keep fluid from passing, and a mechanical latchholds the inner seal in place as its corresponding valve opens andcloses. The design results in two major advantages. First, a heavyhydraulic jack is not required to pull a seat with a worn strike face.This saves considerable time and labor for the operator at a well site.The upper seat can be removed with manual force to overcome the latch.Second, the present invention will result in fewer required valvechanges since operators will change the seat with every valve change. Itis presently common in the industry to install new valves on worn seatssince pulling seats is laborious and time consuming. Having a fresh seatstrike face with every valve change will result in considerably longeraverage valve life and will reduce the time spent replacing valves aswell as seats.

Another advantage of the present invention is that the elastomeric likeseal, which may be urethane, for example, included in the valve and seatarrangement can be placed on the upper seat section rather than on thevalve. Conventional well service valve and seat assemblies place theseal onto the valve, rather than the seat. When the conventional valveis pressed upon the seat with pressure, the tapered seat surfacecompresses at least some of the seal material inward, resulting in highinternal stresses. When the valve of the present invention is pressedonto the seat, the seal is free to expand outward, resulting inrelatively low internal stresses. When the valve is open, the seal isable to deflect and reduce restriction of the fluid flow. When the valveis closed, the seal is able to deflect inward under pressure and form aseal with the valve, even after significant amounts of the elastomericseal have worn away.

Consistent with some embodiments, a valve seat assembly is provided. Theassembly includes a valve and a removable upper seat associated with thevalve. The assembly further includes a lower seat configured to beinserted into a fluid end of a pump and releasably couplable to theupper seat. The upper seat is decouplable from the lower seat while thelower seat remains inserted in the fluid end of the pump. The valve isconfigured to contact the upper seat to prevent a flow of fluid throughthe fluid end of the pump.

Consistent with other embodiments, a valve seat assembly is provided.The assembly includes a valve including an engagement surface. Theassembly further includes a seal configured to prevent a flow of fluidthrough a fluid end of a pump. The assembly further includes a removableupper seat including an engagement surface. The assembly furtherincludes a lower seat configured to be inserted into the fluid end ofthe pump and to be releasably couplable to the upper seat. The upperseat is decouplable from the lower seat while the lower seat remainsinserted in the fluid end of the pump. The engagement surface of thevalve is configured to contact the seal and the engagement surface ofthe upper seat to prevent the flow of fluid through the fluid end of thepump.

Consistent with other embodiments, a valve seat assembly is provided.The assembly includes a valve including an engagement surface. Theassembly further includes a seat insertable into a fluid end of a pump,and the seat includes an engagement surface. The assembly furtherincludes a seal coupled to the seat. The seal is configured to prevent aflow of fluid through the fluid end of the pump, and the seal includes acontact surface. The engagement surface of the valve is configured tocontact the seal and the engagement surface of the seat to prevent theflow of fluid through the fluid end of the pump. The contact between theengagement surface of the valve and the engagement surface of the seatis continuous along the engagement surface of the seat. The engagementsurface of the valve is configured to contact the seal before contactingthe engagement surface of the seat.

A generalized valve seat assembly includes a valve. The assembly furtherincludes a removable upper seat associated with the valve. The assemblyfurther includes a lower seat configured to be inserted into a fluid endof a pump and releasably couplable to the upper seat. The upper seat isdecouplable from the lower seat while the lower seat remains inserted inthe fluid end of the pump. The valve is configured to contact the upperseat to prevent a flow of fluid through the fluid end of the pump.

An additional generalized valve seat assembly includes a valve includingan engagement surface. The assembly further includes a seal configuredto prevent a flow of fluid through a fluid end of a pump. The assemblyfurther includes a removable upper seat including an engagement surface.The assembly further includes a lower seat configured to be insertedinto the fluid end of the pump and releasably couplable to the upperseat. The upper seat is decouplable from the lower seat while the lowerseat remains inserted in the fluid end of the pump. The engagementsurface of the valve is configured to contact the seal and theengagement surface of the upper seat to prevent the flow of fluidthrough the fluid end of the pump.

An additional generalized valve seat assembly includes a valve includingan engagement surface. The assembly further includes a seat insertableinto a fluid end of a pump, and the seat includes an engagement surface.The assembly further includes a seal coupled to the seat. The seal isconfigured to prevent a flow of fluid through the fluid end of the pump,and the seal includes a contact surface. The engagement surface of thevalve is configured to contact the seal and the engagement surface ofthe seat to prevent the flow of fluid through the fluid end of the pump.The contact between the engagement surface of the valve and theengagement surface of the seat is continuous along the engagementsurface of the seat. The engagement surface of the valve is configuredto contact the seal before contacting the engagement surface of theseat.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings illustrate embodiments of the devices andmethods disclosed herein and together with the description, serve toexplain the principles of the present disclosure.

FIG. 1 is a sectioned view of a conventional well service pump valve andseat arrangement.

FIG. 2 is a sectioned view of a valve and seat assembly within a sectionof a fluid end according to one or more aspects of the presentdisclosure.

FIG. 3 is a sectioned view of the valve and seat assembly of FIG. 2 withthe valve in an open position according to one or more aspects of thepresent disclosure.

FIG. 4 is a sectioned view of the valve and seat assembly of FIG. 2 withpressure applied to the valve in a closed position according to one ormore aspects of the present disclosure.

FIG. 5 is a sectioned view of the valve and seat assembly of FIG. 2 withthe valve engaged with the upper seat according to one or more aspectsof the present disclosure.

FIG. 6 is a sectioned view of the valve and seat assembly of FIG. 2 withthe valve and upper seat pulled from the lower seat according to one ormore aspects of the present disclosure.

FIG. 7 is a sectioned partial view of a latch mechanism to help ensurethe upper seat and lower seat stay coupled according to one or moreaspects of the present disclosure.

FIG. 8 is a sectioned partial view showing an alternative latchmechanism according to one or more aspects of the present disclosure.

FIG. 9 is a perspective view of alternative upper and lower seatsincluding the latch mechanism of FIG. 8 according to one or more aspectsof the present disclosure.

FIG. 10 is an exploded perspective view of the alternative upper andlower seats including the latch mechanism of FIG. 8 according to one ormore aspects of the present disclosure.

FIG. 11 is a sectioned view of an alternative valve and seat assemblywith a seal coupled to a valve according to one or more aspects of thepresent disclosure.

FIG. 12 is a sectioned view of an alternative valve and seat assemblywith the valve in an open position according to one or more aspects ofthe present disclosure.

FIG. 13 is a sectioned view of a seal of the alternative valve and seatassembly of FIG. 12 according to one or more aspects of the presentdisclosure.

DETAILED DESCRIPTION

For the purposes of promoting an understanding of the principles of thepresent disclosure, reference will now be made to the embodimentsillustrated in the drawings, and specific language will be used todescribe the same. It will nevertheless be understood that no limitationof the scope of the disclosure is intended. Any alterations and furthermodifications to the described devices, instruments, methods, and anyfurther application of the principles of the present disclosure arefully contemplated as would normally occur to one skilled in the art towhich the disclosure relates. In particular, it is fully contemplatedthat the features, components, and/or steps described with respect toone embodiment may be combined with the features, components, and/orsteps described with respect to other embodiments of the presentdisclosure.

FIG. 1 is a sectioned view of a conventional well service pump valve andseat arrangement 100. The arrangement 100 may have a valve 21 and a seat22. The valve 21 may rest on the seat 22, and the seat 22 may be pressedinto a fluid end 4 of a pump. Therefore, in some embodiments, the seat22 may interact with the fluid end via a tapered press fit 5. In someexamples, through the tapered press fit 5, an outer surface 26 of theseat 22 may contact an inner surface 24 of the fluid end 4. The taperedpress fit 5 may impart friction between the outer surface 26 of the seat22 and the inner surface 24 of the fluid end 4. In some examples, inorder to extract the seat 22 from the fluid end 4, a hydraulic jack (notshown) may be required to overcome the friction between the outersurface 26 of the seat 22 and the inner surface 24 of the fluid end 4.In some embodiments, the valve and seat arrangement may also have aresilient seal 23. The seal 23 may prevent fluid from washing betweenthe valve 21 and the seat 22.

FIG. 2 is a sectioned view of a valve and seat assembly 200 within asection of a fluid end 28 according to one or more aspects of thepresent disclosure. In some embodiments, the assembly 200 includes avalve 1 and a seat 50. In this implementation, the seat 50 is amulti-piece seat that includes an upper seat 2, and a lower seat 3. Theupper seat 2 and lower seat 3 may together, as seat 50, comprise asegmented valve seat positioned between the valve 1 and the fluid end 28of a pump. The upper seat 2 and the lower seat 3 may comprise a quickchange valve seat. In some examples, the upper seat 2 may serve as astrike face for the valve 1, and the upper seat 2 may also be a linerfor the lower seat 3.

As shown in FIG. 2, the valve 1 sits upon the upper seat 2, and theupper seat 2 is releasably connected to the lower seat 3. In someembodiments, the lower seat 3 may be pressed into the fluid end 28 witha tapered fit 29 such that an outer surface 13 of the lower seat 3contacts an inner surface 14 of the fluid end 28. The tapered fit 29 mayimpart friction between the outer surface 13 of the lower seat 3 and theinner surface 14 of the fluid end 28. In several examples, an optionalo-ring 6 is placed between the lower seat 3 and the fluid end 28. Theo-ring 6 may help ensure that there is a seal between the lower seat 3and the fluid end 28. In the embodiment shown in FIG. 2, a hydraulicjack may be required to remove the lower seat 3 from the fluid end 28.However, a much lower force may be required to remove the upper seat 2from the lower seat 3. Additionally, the assembly 200 further includes aresilient seal 7. The seal 7 may be bonded to the upper seat 2.Therefore, in some examples, the seal 7 may be in contact with both thevalve 1 and the upper seat 2. In some examples, the upper seat 2 is madeof metal.

As further shown in FIG. 2, the upper seat 2 includes an engagementsurface 8, an outer surface 40, a channel 42, and an inner contactsurface 44. The embodiment shown in FIG. 2 further illustrates that thelower seat 3 includes an outer surface 60 and an inner surface 62.Additionally, FIG. 2 shows that the seal 7 includes a contact surface36, an upper surface 37, an outer surface 38, and a protrusion 39. Inseveral embodiments, the protrusion 39 of the seal 7 fits within thechannel 42 of the upper seat 2. This may provide for a more secureconnection between the seal 7 and the upper seat 2. In some embodiments,the channel 42 is inwardly spaced from the outer surface 40 of the upperseat 2. The outer surface 38 of the seal 7 defines a diameter Ds. Theouter surface 40 of the upper seat 2 defines a diameter Dus. In someembodiments, when the seal 7 is in a non-compressed state (e.g., whenthe valve 1 is in the open position), the diameter Ds may besubstantially the same as the diameter Dus. In other embodiments, whenthe seal 7 is in a compressed state (e.g., the valve 1 is in the closedposition), the diameter Ds may be larger than the diameter Dus due tooutward deflection of the seal 7 when the seal 7 is compressed.

In some embodiments, one or more legs of a plurality of legs 9 of thevalve 1 may be slideably received within the inner contact surface 44 ofthe upper seat 2 when the valve 1 is in the open position. In severalcases, one or more legs of the plurality of legs 9 may be slideablyreceived within the inner surface 62 of the lower seat 3 as well. Theplurality of legs 9 may be slideably received within the inner surface62 of the lower seat 3 when the valve 1 is in any one of the openposition, the closed position, or both. In alternative embodiments, thelegs 9 may not be slideably received within the inner surface 62.

In some embodiments, because the seal 7 is coupled to the upper seat 2instead of the valve 1, the seal 7 experiences less fatigue than if theseal 7 was coupled to the valve 1. For example, when the valve 1 ispressed onto the upper seat 2, the seal 7 is free to expand outward,resulting in relatively low internal stresses in the seal 7. In someembodiments, when the seal 7 expands outward, the outer surface 38 ofthe seal 7 expands outward beyond the outer surface 40 of the upper seat2 (see FIG. 4). Further, when the valve 1 is open, the seal 7 is able todeflect and reduce restriction of the fluid flow through the pump.Additionally, when the valve 1 is closed, the seal 7 is able to deflectinward under pressure and form a seal with the valve 1.

FIG. 3 is a sectioned view of the valve and seat assembly 200 of FIG. 2with the valve 1 in an open position according to one or more aspects ofthe present disclosure. In the embodiment shown in FIG. 3, the valve 1is lifted off the upper seat 2. In some examples, the valve 1 may belifted off the upper seat 2 by fluid pressure. For example, a pressuredifferential between the engagement surface 11 of the valve 1 and anupper surface 12 of the valve 1 opens the valve 1 and allows fluid toflow in a direction illustrated by arrow 10. Therefore, when the valve 1is in the open position, the engagement surface 11 of the valve 1 isspaced from the engagement surface 8 of the upper seat 2 and from thecontact surface 36 of the seal 7. In several examples, a biasing member(which may be a spring (not shown)) biases the valve 1 towards the upperseat 2 such that the engagement surface 11 of the valve 1 contacts theengagement surface 8 of the upper seat 2 and the contact surface 36 ofthe seal 7.

As shown in the embodiment of FIG. 3, when the valve 1 is in the openposition, the contact surface 36 of the seal 7 is angled with respect tothe engagement surface 8 of the upper seat 2. In this way, the contactsurface 36 and the engagement surface 8 may meet at an angle A. In someembodiments, the angle A is 170°. The angle provided herein is forexample only, and other embodiments may include smaller or largerangles. For example, in some implementations, the angle A may range froman angle smaller than 170° (e.g., 95°-170°) to an angle larger than 170°(e.g., 170°-180). In other embodiments, the angle A may include a rangeof any other suitable angles. In alternative embodiments, the angle A is180°. In such alternative embodiments, the engagement surface 8 of theupper seat 2 and the contact surface 36 of the seal 7 are parallel. Infurther alternative embodiments, the engagement surface 8 of the upperseat 2 and contact surface 36 of the seal 7 may be parallel, and thecontact surface 36 may be proud with respect to the engagement surface8.

FIG. 4 is a sectioned view of the valve and seat assembly 200 of FIG. 2with the valve 1 in a closed position according to one or more aspectsof the present disclosure. In some embodiments, when the valve 1 is inthe closed position, a pressure on the upper surface 12 of the valve 1is greater than a pressure on the engagement surface 11 of the valve 1.Therefore, a sealable connection is made between the valve 1, the upperseat 2, and the seal 7. Accordingly, when the valve 1 is in the closedposition, the engagement surface 11 of the valve 1 contacts theengagement surface 8 of the upper seat 2 and the contact surface 36 ofthe seal 7. In some embodiments, when the valve 1 transitions from theopen position to the closed position, the engagement surface 11 of thevalve 1 contacts the contact surface 36 of the seal 7 before contactingthe engagement surface 8 of the upper seat 2. In other examples, whenthe valve 1 transitions from the open position to the closed position,the engagement surface 11 contacts the contact surface 36 of the seal 7before contacting the upper surface 37. In other embodiments, when thevalve 1 transitions from the open position to the closed position, theengagement surface 11 contacts the upper surface 37 of the seal 7 beforecontacting the contact surface 36. In still other embodiments, when thevalve 1 transitions from the open position to the closed position, theengagement surface 11 contacts the upper surface 37 and the contactsurface 36 at substantially the same time.

In several examples, when the engagement surface 11 of the valve 1contacts the seal 7, the seal 7 is deformed, and the engagement surface11 of the valve 1 then comes to rest upon the engagement surface 8 ofthe upper seat 2 and the contact surface 36 of the seal 7. When theengagement surface 11 of the valve 1 comes to rest upon the engagementsurface 8 of the upper seat 2, the angle A between the contact surface36 of the seal 7 and the engagement surface 8 of the upper seat 2 maygenerally be 180°. In alternative embodiments, when the valve 1transitions from the open position to the closed position, theengagement surface 11 of the valve 1 contacts the contact surface 36 ofthe seal 7 and the engagement surface 8 of the upper seat 2 atsubstantially the same time. In several examples, the engagement surface8 of the upper seat 2 is a hard strike face. In such examples, theengagement surface 11 of the valve 1 is also a hard strike face.Therefore, when the engagement surface 11 of the valve 1 contacts theengagement surface 8 of the upper seat 2, a seal is formed between twohard strike faces. This seal may be complete and unbroken along anentire surface area where the engagement surface 8 is in contact withthe engagement surface 11. Thus, in several embodiments, when the valve1 is in the closed position, there are no breaks in the seal between thehard strike faces of the engagement surface 8 and the engagement surface11, and fluid cannot flow between the engagement surface 8 and theengagement surface 11. The engagement surface 11 of the valve 1 may bemetal or any other suitably hard material. In some examples, theengagement surface 8 of the upper seat 2 may also be metal or any othersuitably hard material. In this way, there may be metal-to-metal contactbetween the engagement surface 8 of the upper seat 2 and the engagementsurface 11 of the valve 1 when the valve 1 is in the closed position.

FIG. 5 is a sectioned view of the valve and seat assembly 200 of FIG. 2with the valve 1 engaged with the upper seat 2 according to one or moreaspects of the present disclosure. Reference will also be made to FIG.6, which is a sectioned view of the valve and seat assembly 200 of FIG.2 with the valve 1 and upper seat 2 pulled from the lower seat 3according to one or more aspects of the present disclosure. Theembodiments of FIGS. 5 and 6 illustrate a disassembly of the segmentedseat 50. In several examples, the valve 1 is pulled upwards for removalin a direction away from the lower seat 3. In some embodiments, theplurality of valve legs 9 have an outer diameter D1. In some examples,the upper seat 2 includes a shoulder 15 that has an inner diameter D2.The outer diameter D1 of the plurality of valve legs 9 may be greaterthan the inner diameter D2 of the shoulder 15 of the upper seat 2. Inseveral embodiments, when the valve 1 is pulled upward, the plurality oflegs 9 engage the shoulder 15, as shown in FIG. 5. Therefore, pullingthe valve 1 upward beyond the position illustrated in FIG. 4 will liftthe upper seat 2 upward as well.

In some embodiments, such as the embodiment shown in FIG. 6, the upperseat 2 includes a mechanical coupler mechanism 17. In some examples, thecoupler mechanism 17 may form a friction fit, such as an interferencefit, between the upper seat 2 and the lower seat 3. The degree ofinterference of the interference fit may range from light interferenceto strong interference. The upper seat 2 may be more easily decoupledfrom the lower seat 3 when the interference fit is a light interferencefit than when the interference fit is a strong interference fit. Inother implementations, the coupler mechanism 17 may be a latchmechanism, a detent mechanism, or any other coupler mechanism. Withreference to FIG. 7, for example, the coupler mechanism 17 may include alatch 19 that utilizes some form of mechanical interference to maintainthe upper seat 2 and the lower seat 3 together in a coupled state. Insome embodiments, the latch 19 is an elastomeric o-ring. In suchembodiments, the latch 19 is a seal. As further shown in FIG. 6, thelower seat may include a bore 20. In embodiments when the latch 19 is aseal, the latch 19 may deform as it is pressed through the bore 20. Inother embodiments, the coupler mechanism 17 may include a coil spring orany other suitable material that deforms during installation as it ispressed through the bore 20. Further discussion regarding embodimentswhen the latch 19 is a seal is provided below with respect to FIG. 7.

In some embodiments, the lower seat 3 includes a groove 16 sized andshaped to receive the coupler mechanism 17. In several examples, whenthe upper seat 2 is lifted upward, the coupler mechanism 17 maydisengage with the groove 16, which results in the upper seat 2 alsobeing removed from the fluid end 4. In such examples, the upper andlower seats 2, 3 are in a decoupled state. In some examples, notches(e.g., notches 25 in FIG. 7) may be machined on the inner diameter D2 ofthe shoulder 15 of the upper seat 2 to facilitate the assembly of thevalve 1 and the upper seat 2 with greater ease. The amount ofdiametrical interference between the outer diameter D1 of the pluralityof legs 9 and the inner diameter D2 of the shoulder 15 may be such thatpressing the valve 1 through the upper seat 2 (e.g., when installing theassembly 200) will not result in permanent deformation of eithercomponent in the event the notches 25 are not present.

As shown in the embodiment of FIG. 6, the upper seat 2 further includesa lower engagement surface 46, a latch surface 48, and a lower contactsurface 49. As further shown in FIG. 6, the lower seat 3 furtherincludes an engagement surface 64, a latch surface 66, and a contactsurface 68. In some embodiments, the lower engagement surface 46 and thelatch surface 48 may meet at an angle B. In some embodiments, the angleB is 100°. The angle provided herein is for example only, and otherembodiments may include smaller or larger angles. For example, in someimplementations, the angle B may range from an angle smaller than 100°(e.g., 90°-100°) to an angle larger than 100° (e.g., 100°-180°). As oneexample, the angle B may range from 0° to 180°. In other embodiments,the angle B may include a range of any other suitable angles.

With respect to the upper seat 2, in some embodiments, the lowerengagement surface 46 may not be parallel with the engagement surface 8.In other embodiments, the lower engagement surface 46 may not beparallel with the lower contact surface 49. In alternative embodiments,though, the lower engagement surface 46 may be parallel with one or bothof the engagement surface 8 and the lower contact surface 49.

With reference to FIG. 5, when the upper seat 2 and the lower seat 3 arein a coupled state, the lower engagement surface 46 of the upper seat 2is in contact with the engagement surface 64 of the lower seat 3. Thelower engagement surface 46 may be generally parallel with theengagement surface 64. As further shown in FIG. 5, when the upper seat 2and the lower seat 3 are in the coupled state, the latch surface 48 ofthe upper seat 2 is slideably received within the latch surface 66 ofthe lower seat 3. Additionally, FIG. 5 illustrates that when the upperseat 2 and the lower seat 3 are in the coupled state, the lower contactsurface 49 of the upper seat 2 may not contact the contact surface 68 ofthe lower seat 3 (e.g., the lower contact surface 49 may be spaced fromthe contact surface 68). In other embodiments, when the upper seat 2 andthe lower seat 3 are in the coupled state, the lower contact surface 49of the upper seat 2 may be in contact with the contact surface 68 of thelower seat 3. The lower contact surface 49 may be generally parallelwith the contact surface 68.

As discussed above, the upper seat 2 may be decoupled from the lowerseat 3 as a result of the plurality of legs 9 of the valve 1 engagingthe shoulder 15 of the upper seat 2 when the valve 1 is pulled upward.As shown in the embodiment of FIG. 6, when the upper seat 2 and thelower seat 3 are in the decoupled state, the lower engagement surface 46of the upper seat 2 is spaced from the engagement surface 64 of thelower seat 3.

FIG. 7 is a sectioned partial view of the coupler mechanism 17, whichhelps ensure the upper seat 2 and lower seat 3 stay together accordingto one or more aspects of the present disclosure. In some embodiments,once installed, the coupler mechanism 17 expands into the groove 16 ofthe lower seat 3. Additionally, as discussed above, in embodiments whenthe latch 19 is a seal, the seal 19 prevents fluid from passing betweenthe upper seat 2 and the lower seat 3. As further discussed above withrespect to FIG. 6, in some examples, the coupler mechanism 17 forms aninterference fit between the upper seat 2 and the lower seat 3. In suchexamples, the interference fit maintains the upper seat 2 and the lowerseat 3 in the coupled configuration. The degree of interference of theinterference fit may range from light interference to stronginterference. The upper seat 2 may be more easily decoupled from thelower seat 3 when the interference fit is a light interference fit thanwhen the interference fit is a strong interference fit. In severalexamples, a seal 18 prevents fluid from passing between the upper seat 2and the lower seat 3. In some embodiments, a plurality of notches 25pass through the shoulder 15 and provide a passage for the valve 1 to beassembled with the upper seat 2.

FIG. 8 is a sectioned partial view showing an alternative latchmechanism 32 and valve assembly 300, which includes upper and lowerseats 31, 33 according to one or more aspects of the present disclosure.FIG. 9 is a perspective view of valve assembly 300. FIG. 10 is anexploded perspective view of the upper and lower seats 31, 33 includingthe latch mechanism 32 of FIG. 8 according to one or more aspects of thepresent disclosure. The upper seat 31 may be substantially similar toand include substantially all the features of the upper seat 2, and anydifferences will be discussed in further detail below. The lower seat 33may be substantially similar to and include substantially all thefeatures of the lower seat 3, and any differences will be discussed infurther detail below.

In several embodiments, the upper seat 31 may include a latch mechanism32. The latch mechanism 32 may include a plurality of tabs 35 spacedaround a perimeter of the upper seat 31. In several examples, theplurality of tabs 35 may be equidistantly spaced around the perimeter ofthe upper seat 31. The number of tabs may vary, but may be within arange of two to 100 tabs, although more or fewer tabs are contemplated.In alternative examples, the plurality of tabs 35 may benon-equidistantly spaced around the perimeter of the upper seat 31. Insome examples, the lower seat 33 includes a groove 34 sized and shapedto receive the plurality of tabs 35. As shown in the embodiment of FIG.8, when the upper seat 31 is pressed onto the lower seat 33, each tab ofthe plurality of tabs 35 snaps into the groove 34 on the lower seat 33.In some embodiments, the plurality of tabs 35 may be a metallicmaterial. In such embodiments, the plurality of tabs 35 may act as acantilever spring so that each tab of the plurality of tabs 35 does notyield before each tab snaps into the groove 34.

FIG. 11 is a sectioned view of an alternative valve and seat assemblywith a seal coupled to a valve according to one or more aspects of thepresent disclosure. In alternative embodiments, an alternative valveassembly 500 includes the valve 1, the seat 50, which includes the upperseat 2 and the lower seat 3, and a seal 510. The seal 510 may be bondedto the valve 1. As further shown in FIG. 11, the seal includes a contactsurface 512. In several examples, when the contact surface 512 contactsthe engagement surface 8 of the upper seat 2, the seal 510 is deformed,and the engagement surface 11 of the valve 1 then comes to rest upon theengagement surface 8 of the upper seat 2. In some embodiments, when thevalve 1 transitions from the open position to the closed position, thecontact surface 512 of the seal 510 contacts the engagement surface 8 ofthe upper seat 2 before the engagement surface 11 of the valve 1contacts the engagement surface 8. In still other embodiments, when thevalve 1 transitions from the open position to the closed position, thecontact surface 512 and the engagement surface 11 contact the engagementsurface 11 at substantially the same time.

FIG. 12 is a sectioned view of an alternative valve and seat assemblywith the valve in an open position according to one or more aspects ofthe present disclosure. In alternative embodiments, an alternative valveassembly 400 includes a valve 410, a seat 420, and a seal 430. The valve410 may be substantially similar to the valve 1 of FIG. 2. The seal 430may be substantially similar to the seal 7 of FIG. 2. The seal 430 maybe bonded to the seat 420. Therefore, in some examples, the seal 430 maybe in contact with both the valve 410 and the seat 420. In severalembodiments, the seat 420 is one, single component. In some examples,the seat 420 is made of metal.

In several examples, the seat 420 may function in the same manner as thecombination of the upper and lower seats 2, 3 of FIG. 2. For example, asdiscussed above with respect to FIG. 2, in some embodiments, the seat420 may be pressed into the fluid end 28 of a pump, as shown in FIG. 2.In some examples, the seat 420 includes a tapered fit such that an outersurface 422 of the seat 420 contacts an inner surface 14 of the fluidend 28. The tapered fit may impart friction between the outer surface422 of the seat 420 and the inner surface 14 of the fluid end 28.

In some embodiments, a hydraulic jack may be required to overcome thefriction between the outer surface 422 of the seat 420 and the innersurface 14 of the fluid end 28 in order to extract the seat 420 from thefluid end 28. In such embodiments, the seal 430 experiences less fatiguethan if the seal 430 was bonded to the valve 410. For example, when thevalve 410 is pressed onto the seat 420, the seal 430 is free to expandoutward, resulting in relatively low internal stresses. Further, whenthe valve 410 is open, the seal 430 is able to deflect and reducerestriction of the fluid flow through the pump. Additionally, when thevalve 410 is closed, the seal 430 is able to deflect inward underpressure and form a seal with the valve 410.

As further shown in FIG. 12, the seat 420 includes an outer surface 422,an engagement surface 424, and an inner surface 425. The embodimentshown in FIG. 12 further illustrates that the seal 430 includes an outersurface 432, a contact surface 434, and an upper surface 436. The seal430 will be discussed in greater detail below with respect to FIG. 13.In some embodiments, a plurality of legs 405 of the valve 410 may beslideably received within the inner surface 425 of the seat 420 when thevalve 410 is in the open position. This contact may occur when the valve410 is in any one of the open position, the closed position, or both. Inalternative embodiments, the legs 405 may not contact the inner surface425.

In some examples, when the valve 410 is in the open position, an outersurface 432 of the seal 430 is substantially parallel with the outersurface 422 of the seat 420. In alternative embodiments, when the valve410 is in the open position, the outer surface 432 of the seal 430 mayextend outward beyond the outer surface 422 of the seat 420. In furtheralternative embodiments, when the valve 410 is open, the outer surface432 of the seal 430 may extend inward toward an engagement surface 412of the valve 410. In some embodiments, when the valve 410 is in theclosed position, the seal 430 may expand outward, and the outer surface432 of the seal 430 may expand outward beyond the outer surface 422 ofthe seat 420.

In several embodiments, as fluid flows past the valve 410, in adirection of flow illustrated by the arrow 10 (FIG. 3), a pressuredifferential between the engagement surface 412 of the valve 410 and anupper surface 414 of the valve 410 opens the valve 410 and allows fluidflow. Therefore, when the valve 410 is in the open position, theengagement surface 412 of the valve 410 is spaced from an engagementsurface 424 of the seat 420 and from the seal 430. In several examples,a biasing member (which may be a spring (not shown)) biases the valve410 towards the seat 420 such that the engagement surface 412 of thevalve 410 contacts the engagement surface 424 of the seat 420 and theseal 430.

In some embodiments, when the valve 410 is in the closed position, apressure on the upper surface 414 of the valve 410 is greater than apressure on the engagement surface 412 of the valve 410. Therefore, asealable connection is made between the valve 410, the seat 420, and theseal 430. Accordingly, when the valve 410 is in the closed position, theengagement surface 412 of the valve 410 contacts the engagement surface424 of the seat 420 and the seal 430. In some embodiments, when thevalve 410 transitions from the open position to the closed position, theengagement surface 412 of the valve 410 contacts the seal 430 beforecontacting the engagement surface 424 of the seat 420. In severalexamples, when the engagement surface 412 of the valve 410 contacts theseal 430, the seal 430 is deformed, and the engagement surface 412 ofthe valve 410 then comes to rest upon the engagement surface 424 of theseat 420 and the contact surface 434 of the seal 430. When theengagement surface 412 of the valve 410 comes to rest upon theengagement surface 424 of the seat 420, the angle C between the contactsurface 434 of the seal 430 and the engagement surface 424 of the seat420 may generally be 180°. In some embodiments, when the valve 410transitions from the open position to the closed position, theengagement surface 412 contacts the contact surface 434 of the seal 430before contacting the upper surface 436. In other embodiments, when thevalve 410 transitions from the open position to the closed position, theengagement surface 412 contacts the upper surface 436 of the seal 430before contacting the contact surface 434. In still other embodiments,when the valve 410 transitions from the open position to the closedposition, the engagement surface 412 contacts the upper surface 436 andthe contact surface 434 at substantially the same time.

In several examples, the engagement surface 424 of the seat 420 is ahard strike face. In such examples, the engagement surface 412 of thevalve 410 is also a hard strike face. Therefore, when the engagementsurface 412 of the valve 410 contacts the engagement surface 424 of theseat 420, a seal is formed between two hard strike faces. This seal maybe complete and unbroken along an entire surface area where theengagement surface 424 is in contact with the engagement surface 412.Thus, in several embodiments, there are no breaks in the seal betweenthe hard strike faces of the engagement surface 424 and the engagementsurface 412. When the valve 410 is in the closed position, fluid cannotflow between the engagement surface 424 and the engagement surface 412.The engagement surface 412 of the valve 410 may be metal or any othersuitably hard material. In some examples, the engagement surface 424 ofthe seat 420 may also be metal or any other suitably hard material. Inthis way, there may be metal-to-metal contact between the engagementsurface 424 of the seat 420 and the engagement surface 412 of the valve410 when the valve 410 is in the closed position.

FIG. 13 is a sectioned view of a seal of the alternative valve and seatassembly of FIG. 12 according to one or more aspects of the presentdisclosure. As shown in the embodiment of FIG. 13, the seal 430 furtherincludes a protrusion 438. Additionally, FIG. 13 illustrates that theseat 420 includes a channel 426. In several embodiments, the protrusion438 of the seal 430 fits within the channel 426 of the seat 420. Thismay provide for a more secure connection between the seal 430 and theseat 420. In some embodiments, the channel 426 is inwardly spaced fromthe outer surface 422 of the seat 420. In some embodiments, when theseal 430 is in a non-compressed state (e.g., when the valve 410 is inthe open position), the upper surface 436 of the seal 430 may besubstantially perpendicular to the outer surface 432 of the seal 430. Inother embodiments, the upper surface 436 and the outer surface 432 maynot be perpendicular such that when the seal 430 is in a non-compressedstate, the outer surface 432 extends outward beyond the outer surface422 of the seat 420.

As further shown in the embodiment of FIG. 13, when the valve 410 is inthe open position, the contact surface 434 of the seal 430 may be angledwith respect to the engagement surface 424 of the seat 420. In this way,the contact surface 434 and the engagement surface 424 may meet at anangle C. In some embodiments, the angle C is 170°. The angle providedherein is for example only, and other embodiments may include smaller orlarger angles. For example, in some implementations, the angle C mayrange from an angle smaller than 170° (e.g., 95°-170°) to an anglelarger than 170° (e.g., 170°-180°). In other embodiments, the angle Cmay include a range of any other suitable angles. In alternativeembodiments, the angle C is 180°. In such alternative embodiments, theengagement surface 424 of the seat 420 and the contact surface 434 ofthe seal 430 are parallel.

Persons of ordinary skill in the art will appreciate that theembodiments encompassed by the present disclosure are not limited to theparticular exemplary embodiments described above. In that regard,although illustrative embodiments have been shown and described, a widerange of modification, change, and substitution is contemplated in theforegoing disclosure. It is understood that such variations may be madeto the foregoing without departing from the scope of the presentdisclosure. Accordingly, it is appropriate that the appended claims beconstrued broadly and in a manner consistent with the presentdisclosure.

The invention claimed is:
 1. A method comprising: releasably coupling,by a latch of a valve seat assembly for a fluid end of a pump, aremovable upper seat of the valve seat assembly and a lower seat of thevalve seat assembly, the removable upper seat associated with a valve ofthe valve seat assembly to permit unidirectional flow of fluid, thelower seat configured to be inserted into the fluid end of the pump, andthe upper seat and the lower seat defining an axis through the valveseat assembly; and receiving, by the upper seat, a separating forceapplied in an axial direction; and releasing, by the latch, the upperseat from the lower seat only in response to receiving the separatingforce.
 2. The method of claim 1, wherein the latch is a deformable ringextending around an outer wall of the upper seat and in contact with aninner surface of the lower seat.
 3. The method of claim 1, wherein thelatch is an elastically deformable ring.
 4. The method of claim 1,wherein the latch is a deformable ring disposable in grooves formed infacing surfaces of the upper seat and the lower seat.
 5. The method ofclaim 4, wherein releasably coupling the upper seat and the lower seatincludes mechanically preventing, by only the deformable ring, removalof the upper seat from the lower seat.
 6. The method of claim 1, furthercomprising preventing, by the valve, a flow of fluid through the fluidend of the pump when the valve is in contact with the upper seat.
 7. Amethod comprising: releasably coupling, by a latch of a valve seatassembly for a fluid end of a pump, a removable upper seat of the valveseat assembly and a lower seat of the valve seat assembly, the upperseat comprising a shoulder and a plurality of guide notches, theplurality of guide notches formed in an inner surface of the upper seat,the lower seat configured to be inserted into the fluid end of the pump,and the upper seat and the lower seat defining an axis through the valveseat assembly; receiving, by a valve of the valve seat assembly, aseparating force applied in an axial direction; contacting, by aplurality of legs of the valve, the shoulder of the upper seat inresponse to receiving the separating force; and removing, by theplurality of legs, the upper seat from the lower seat in response to theplurality of legs contacting the shoulder of the upper seat.
 8. Themethod of claim 7, wherein the latch is a deformable ring extendingaround an outer wall of the upper seat and in contact with an innersurface of the lower seat.
 9. The method of claim 7, wherein the latchis an elastically deformable ring.
 10. The method of claim 7, furthercomprising preventing, by the valve, a flow of fluid through the fluidend of the pump when the valve is in contact with the upper seat.